Apparatus for producing seamless hollow bodies of felted fibrous material



Marcl1 11,1947. MQRNEWBOULD ,4 7, 7

APPARATUS FOR PRODUCING SEAMLESS HOLLOW BODIES OF. FELTED FIBROUSMATERIAL A Filed Feb. 15, 1943 A 4 Sheets-Sheet 1 "Fig 1a.-

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M. G. R. NEWBOULD 9417, 375 APPARATUS FOR PRODUCING SEAMLESS HOLLOWBODIES OF FELTED FIBROUS MATERIAL Filed Feb. 15, 1943 4 Sheets-Sheet 2March 11, 194-7. m .R. NEWBO U 2,417,375

' APPA ilgII-lJLow .G RATU OR PRCDUCING SEA SS BODIES OF FELTED FIBROUSMATER Filed Feb. 15, 1945 4 Sheets-Sheet 3 March 11, 1947. M. G.2,417,375

APP TUS FOR RIJ-ZIXIELOW I ESS TE R. NEWBOULD PROD ING SEAML D ES OFFELTE I ROUS MA Filed Feb. 1943 4 Sheets-Sheet 4 Patented Mar. 11, 1947APPARATUS FOR PRODUCING SEAMLESS HOLLOW BODIES OF FELTED FIBROUSMATERIAL Maurice George Robert Newbould, London S. W. 1, England,assignor to Papercrete Limited,

London, England Application February 15,1943, Serial No. 476,026

In Great Britain March 6, 1942 Claims.

This invention relates to the production of hollow bodies of feltedfibrous material by the aspiration of a fluent fibrous pulp against thesurface of a foraminous member.

The processes for the manufacture of seamless hollow bodies in themanner above referred to may broadly be divided into two classes,namely, (a) that in which the fluent fibrous pulp is introduced within aforaminous mould with which may be associated an expansible andcontractable core element, the extraction from the mouldof the bodyformed by the felted mass of deposited the core element and carried bythe outer mould materia1 being effected by causing it to contract,

and (b) that in which the fibrous component of a fluent fibrous pulp isdeposited on a foraminous core element which in certain cases has beenarranged so that it may be expanded and. contracted, the outer mouldelement in such case being a rigid non-foraminous member or a membercomprising a plurality of sections adapted to be moved toward and awayfrom the body formed on the inner mould element.

The object of the present invention is to provide an improved process ofand apparatus for forming seamless hollow bodies by the deposition ofthe fibrous component of a fluent fibrous pulp on the outer surface of aforaminous core element co-operating with an outer expansiblenon-foraminous mould element or overform.

According to the invention. the body formed by the deposition of thefibrous component of the fluent fibrous pulp on the foram nous coreelement is subjected to compression and is thereafter expanded ordistended to free it from the core element and is transported by theouter mould element or overform which is correspondingly expanded to aposition where the felted mass of fibrous material may be dried orfurther treated, after it has been freed from the outer mould oroverform as the result of its further expansion.

Normally after the fluent fibrous pulp has been deposited on theforaminous core element, a considerable proportion of the residual watercontained in the deposited layer of fibrous component is removed byaspiration of air through the fibrous material deposited on the innermould element.

Apparatus according to the invention comprises an outer non-foraminousmould element or overform so constructed and arranged that it may becontracted to consolidate the felted mass of fibrous material depositedon the core element and thereafter expanded to a degree sufficient toenable the felted mass to be freed from element" or overform to, anddeposited by the further expansion or distension of the overform whichfrees or detaches the felted mass from it, at the position wherethefelted mass of fibrous material may be dried or further treated.

Preferably, in accordance with the invention, the outer non-foraminousmould element is so construcmd and arranged that it may be expanded andcontracted by producing a difierence in the pressure operating on itsinner and outer surfaces. 7

Thus, in accordance with the invention, the outer non-foraminous mould.element may be formed mainly of a flexible or elastic material such asrubber provided with reinforcements adapted to restrict its distortionwithout restricting its expansion or distension and may be secured wthin a chamber furnished with connections whereby the pressure betweenthe walls of the chamber and the flexiblenon-foraminous mould elementmay be varied in order to, effect or permit of its expansion andcontraction.

As above indicated, two degrees of expansion are provided for and anyappropriate means may be employed to limit the degree of expansion toenable the article formed of the felted mass of fibrous material to bedetached from the foraminous core element and to be supported by theouter mould element so that it may be carried to the place where theformed body is to be dried or further treated, and thereafter to beexpanded in order that the outer mould element may be freed from theformed body.

For controlling the expansion and limiting the distortion of the outerflexible mould element, it may be provided witha plurality of spaced semental elements of relatively rigid material extending from a positionadjacent to its top, and

with each of these members there may be pivotally connected at two ormore points in its length and thus at two or more zones in the height ofthe outer flexible mould element levers in turn pivotally connected withthe outer rigid casing, the outer ends of the levers positioned at eachof the zones being connected together by, for instance, a ring withwhich is associated a ram or rams operating in a cylinder or cylindersconnected with a reservoir into which and from which water will bedisplaced in the expansion sired distortion, a disc preferably facedwith Wire gauze may be associated with the upper end of the flexiblemould element, the disc bein'g pro-' vided withan extension slidable inguides provided in the casing or chamber with which the flexible mouldelement is associated.

I To assist in freeing the body of felted fibrous material'from theforaminous core element means may-be'provided for introducing air underpressure into the core element and to assist in detaching, the formedbody of felted fibrous material from the outer mould element or overformmeans may be provided for introducing air under pressure between thesurface of the formed body and the inner surface of the outer mouldelement or-overform.

To retainthe body of felted fibrous material in position in the outermould element or overform in order that the body may be carried by themould element'to its position for further treatment, meansmay beprovided for producing a pressure below atmospheric pressure between theformed body and the surface of the disc forming the end of the outermould element or overform in contact with it, in which case theconnection with the means for producing the reduced pressure will beinterrupted at anappropriate time to enable theformed body of feltedfibrous material to become detached, air under a pres sure in excess ofatmospheric pressure being normally thereafter introduced between thesurface of the formed body and the surface of the inner mould element oroverform to assist in detaching the formed body from the flexible outermould: element which will be distended to its maximum extent tofacilitate such detachment and to enable it to be again brought intoposition over the core element after the stuff chamber has beenrecharged with pulp and a further body formed of fibrous pulp has beendeposited upon the foraminous core.

To enable the outer mould element to be moved into position with respectto the core element for compressing the hollow body and to be removedfrom this position taking with it the formed body, the outer mouldelement may be associated with means for lowering it into position forthe moulding operation, and thereafter moving it into a position inwhich the article is to be deposited or detached from the outer mouldelement or overform for further treatment.

Such means may comprise a crane or the like. The connection of the outermould element with the crane or the like may be associated with meansfor releasably locking the outer mould element against the seatingprovided on the base of the foraminous core element. 1

The connection may, for example, comprise spring urged toggle links soarranged that when the outer mould element is in position over theforaminous core element, the toggle levers will move about theirconnections to cause link ele- 4 ments associated with them to engage inrecesses provided in an extension of the chamber into which the fluentfibrous pulp is introduced and in which is contained the foraminous coreelement, the stuff chamber being provided with means for introducing thefluent fibrous pulp and an overflow arranged at an appropriate height toensure that the pulp, when introduced, does not exceed the desiredlevel, means for withdrawing at appropriate times the excess of pulp andmeans for draining away the water passing through the foraminous coreelement and optionally drawing air through the body of felted fibrousmaterial formed thereon. V V

The foraminous core element may be secured to a base providing a seatingfor the lower edge of the chamber with which the outer mould element isassociated in order that a gas and liquidtight joint may be securedbetween the outer mould element and the base on which theforaminous coreelement is secured.

The base of the foraminous inner core element will normally be locatedin a'stuff chest, that is to say, a chamber'into which the fluentmass offibrous material is introduced and atrthe upper endof this chamber meansmay be provided as above indicated for locking the outer mould elementinto position so that its lower end will be firmly. engaged on theseating.

The invention will be described further. in detail and by way of examplewith reference to the construction shown in the accompanying draw ings,in which:

Figures 1a and 1b are respectively composite views insectional'elevation showing the various working parts. v V

Figures 2a and 2b are respectively a left-hand half section and aright-hand halfsection on a plane indicated by the line A-A in Figure1a, one half showing certain elements inone position, and the other halfshowing the elements in another position.

Figure 3 is a vertical cross section on a plane,

indicated by the line BB in Figure 2b.

The construction illustrated comprises essentially a stuff chamber Iinto which the fluentfibrous pulp is introduced by way of an inlet 2 atthe base of the chamber which adjacent to its upper portion is furnishedwith an overflow3 at an appropriate height above the upper end of theforaminous core element which is secured to a base provided within thechamber.

The core element comprises an inner member 4 extending from the base 5to a position close to the top of the core element, the purpose of whichis to limit or reduce'the free space within 7 the core element.

In the construction illustrated, the inner member 4 is a vessel open atits upper end and in operation of the apparatus it will become filledwith the water separating from the pulp and thus, in

efifect, will operate as a solid member in limiting or reducing the freespace'within the core ele- V In operation, the, outer mould beingraised, the fluent fibrous pulp will be introduced into the stuifchamber through a. stuff inlet pipe 2. The water component of the pulpwill pass through the wire gauze covering of the inner mould ele-- ment,and its suspended fibres will be deposited on the exterior surfacethereof.

This water is, however, not allowed to pass away through the opening 9providedin the base of the core element and the pipe it associatedtherewith as a valve (not shown) associated with this pipe will be keptclosed until the level of the stufi in the stuff chamber reaches apredetermined height above the top of the wire gauze covering.

In starting up the apparatus some of the separated water will flow intothe inner member t which will thereafter remain filled with water andthus in effect function as a solid body.

The purpose of this inner member 4 is to reduce the effective volume ofthe interior of the core member and thus ensure the raising of the levelof the pulp in the pulp chamber at a greater rate than would be possibleif the inner member Were not provided, which in turn operates to preventan undue thickening of the deposited layer at a position adjacent to thelower end of the core member.

When the liquid has risen to the predetermined height, the valveassociated with the pipe i!) will be opened and water will be suckedaway, the pipe being connected to some source of suction, the stuffbeing continuously supplied until the layer of fibrous materialdeposited on the foraminous core element has reached the desiredthickness, after which the supply of the fluent fibrous pulp will beinterrupted and the Water in the foraminous core element will continueto be sucked away through the pipe in and an outlet valve on the pipe iiwill be opened to permit the escape of the excess stuff from the stuffchamber. After this air is sucked through the deposited layer of feltedfibre by the connection of the pipe it! with a vacuum pump.

The outer mould element is then brought into position over the coreelement.

This outer mould element comprises essentially an outer casing i2furnished at its lower end with a surface 43 adapted to co-operate witha seating It provided on the base 5 supporting the foraminous coreelement and at its upper end with a disc i5 furnished with a tubularstem iii slidable in a guide I! provided in the cover I8 of the casingto which is secured means for raising and lowering the outer mouldelement.

Within the outer casing there is located a sleeve formed of two layersof rubber is, [to secured at its upper end to the disc 55 above referredto by means of a clamping ring i511, the disc being covered with wiregauze i 5b, the lower end of the sleeve being clamped to a ring 25 byretaining ring 28a and connected with the lower end of the outer casing12 which is formed, as above stated, with a seating surface 53 adaptedto make a fluid-tight joint at M with the base 5 to which the foramincuscore element is secured.

The sleeve is furnished with a plurality of segmental slats 2| of steelor the like located between the two layers of rubber 19, Na extendingfrom a point adjacent to its upper end to a point adjacent to its lowerend to permit thedistension and contraction, of the sleeve butpreventing its distortion and with each of these slats there isconnected, at, a, position adjacent to its 6 upper end by a pin 38, alever 22 secured on a pivot 23 provided in an annular chamber. 24 aboutthe outer casing (see also Figures 2a and 2b), a similararrangementbeing provided adjacent to the lower end of each of theslats.

The levers of the upper and lower sets thereof .are each connected to aring 25 rotatable in guidesin one of the annular chambers, and with eachof these rings there is associated rams 26 operating in cylinders 21connected with a res: ervoir 21a (Figure 3), a valve being provided inthe connection 28, see Figure 3, between each cylinder and the reservoirfor establishing and interrupting communication between the cylindersand reservoir.

Means is provided at lfia for introducing air under pressure into thespace between the sleeve and the outer casing of the outer mould elementin order that the sleeve may be forced against the deposited mass offelted fibrous material in order to consolidate it.

On the introduction of air under pressure by way of the pipe 16a intothe space between the sleeve l9 and the outer case E2 of the outer mouldelement the sleeve contracts initially by an amount equal to the lostmotion provided by the holes 29 in the levers 22 .in which the pins 30are engaged and upon further contraction which is promoted by the actionof air under pressure the sleeve by means of its connections with thelevers, causes rotation of the ring 25 in a clockwise direction therebycausing a, linear motion of the rams 26 inthe cylinders 27..

The valve between the cylinders and the reservoir is at this time openso that the cylinders fill with water;

The layer of fibre deposited on the inner case element is thusconsolidated and when astate of equilibrium is reached, this valve isclosed. The space between the ram and the closed end of the cylinderremains fiiled with water. The airpressure between the rubber sleeveandthe outer casing is released. This causes no motion of the sleeve ,orparts connected with it, as the sleeve is so dimensioned that it willfit tightly or under some tension over the body of felted materialformed on the foraminous core element.

Air pressure is now introduced in the foraminous core element by way ofthe pipe 3|, causing a distension of the web and the sleeve with it,equivalent to the lost motion or slack in the sleeve bracket provided bythe holes 29 in which the pins 30 are engaged with the levers 22 Anyfurther distension of the bag isnow resisted by the reaction of thewater in the cylinders, i. e. a pressure is created within the cy1inderto resist further movement of the levers and sleeve. However, by thistime the web (or felted fibrous layer) is freed from the foraminous coreelement. Coincident with the taking up of this lost motion a vacuum or acondition of reduced pressure is normally produced within the spacebetween the sleeve and the outer casing by connection of the pipe ledwith a pump.

This serves to keep the sleeve and also the web sufficiently distendedand simultaneously a sub-atmospheric pressure is admitted to hollowspindle i5 and so through the gauze face of disc i5 to the outer side ofthe formed hollow body so enabling the web to be lifted away from theforaminous core element.v

The outer mould element is then raised and for raising it, as aboveindicated, it may be associated with a crane adapted, not only to lowerit but to swing the outer mould element into the body may be depositedon means for eiiecting its further treatment as, for instance, on adrying frame, the hookof the crane being engaged with a shackle on theend of the rod 32. f

' When the outer mould element is this position the connection betweenthe reservoir and the rams controlling the motion of the levers isopened and the pressure between the, walls of the sleeve and the outercasing of the outer mould element is, if necessary, further reduced byconnection of the pipe 56a with a vacuum pump or the like.

The sleeve is thus distended or expanded and at this time orsubsequently air under pressure is introduced past the disc 55 by way ofthe pipe i6 and through the gauze and thus about the end and walls ofthe formed body, these two operations resulting in the detachment of themoulded body of material from the outer mould element, after which theouter mould element while still distended may be returned into theposition in which it is suspended above and subsequently lowered overthe foraminous core element.

In order that when it is lowered it may be locked in position over thecore element durin the pressing operation by the sleeve in consolidatingthe felted fibrous material, a system of links 33 may be arranged withthe shackle by which the outer mould element is secured to the crane,the links being associated with a spring or springs 34 adapted to causethem to force outward means 35 adapted. to engage in recesses 36provided on the upper portion of the stufi chamber.

To wash away any fibrous material adhering to the foraminous coreelement after the removal of one formed hollow, body and prior to thereintroduction of the foraminous pulp into the stuff chamber, water isadmitted by way of the pipe 31 connected to the distributor 38, thewater so admitted operating to flush the forarninous member.

As will be understood a seamless hollow body formed of a plurality ofindependently consolidated layers of fibrous pulp may be produced by theapparatus described, in which case the overform or outer mould elementwill be brought into position with respect to the foraminous coreelement at appropriate times in order to consolidate the individuallydeposited layers, the deposition of such layers being secured'by theintroduction of a further body of fluent pulp after the layer previouslydeposited on the core element has been consolidated on removal therefromin the manner generally above described.

Where, as may be desirable, material additional to that forming thefluent fibrous pulp is introduced into the stud chamber for the purpose,for instance, of reducing the porosity of the formed body of feltedfibrous material or renexpansible and contractable non-foraminous mouldelement, a casing surroundin said nonforaminous mould element, meanssupporting the mould element and said casing in spaced relation tothecore element, means for introducing air under pressure into the casingfor contracting the mould element to compress-said body of fibrousmaterial on the core element, meansfor expanding the non-foraminousmould element on sufiicient for the body of fibrous material to be adetached from the foraminous core element and to'be retained within themould element, means for raising the mould element, and meansforreleasing the limiting means to accommodate, further expansion of thenon-foraminous mould element to facilitate release of the fibrous body.

2. Apparatus for forming seamless hollow bodies by aspiration of aliquid suspension of fibrous pulp comprising, a yet, a foraminous coreelement in said vat, means for introducing a liquid suspension offibrous pulp between the innersurface of the vat and the outer surfaceof the core element, means for withdrawing liquid which separates fromthe pulp and passes through the ioraminous core element leaving a bodyof fibrous material thereon, an expansible and contractable non-foraminous mould element, a casing surrounding said'm'ould element andsecured to the lower extremity thereof, a seating surface on the lowerend of said casing, a seating surface carried by said vat for engagementby the first dering it waterproof, these materials may be introducedwith the fluent pulp or subsequently.

I claim: V

1. Apparatus for forming seamless hollow bodies by aspiration of aliquid suspension of fibrous pulp comprising, a vat, a foraminous coreelement in said vat, means for introducing a liquid suspension offibrous pulp between themner surface of the vat and the outer surface ofthe foraminous core element, means for Withdrawing liquid whichseparates from the pulp through the foramin'ous core element leavingabody of fibrous material deposited thereon, an

seatin surface and suppcrtingthe mould element and said casing in spacedrelation to said core element,.means for introducing air under pressureinto said casing contracting the mould element to compress the fibrousmaterial on the core element, means for introducing air under pressureinto the foraminous core element to expand and facilitate detachment ofthe fibrous material therefrom, means limiting the expansion of themould element, means for raising the mould element, and means forreleasing the limiting means to accommodate further expansion of themould element, a

3. Apparatus for forming hollow bodies by aspiration of a liquidsuspension of fibrous pulp comprising, a vat, a foraminous core elementin said vat, means for introducing a liquid suspension of fibrous pulpbetween the inner surface of the vat and the outer surface of theforaminous core element, means for withdrawing iiquid which separatesfrom the pulp and passes through the foraminous core element leaving abody of fibrous material thereon, an expansible and contractablenon-foraminous mould element, formed mainly of rubber having spacedrelatively. rigid slots therein grouped to provide segmental elements,levers connected to the segmental elements, "a casing surrounding saidnon-foraminous mould element, pivotal connections on said'casing forsaid levers, a ring around said casingja connec element, means forexpandingrthe non-forame inous mould element, said interrupting meanslimiting expansion of said mould element to an extent sufiicient toenable the fibrous body to be detached from said core element, means forraising the mould element, and said interrupting means being operable toenable further expansion of the mould element to facilitate release ofthe fibrous body.

4. Apparatus for forming hollow bodies by aspiration of a liquidsuspension of fibrous pulp comprising, a vat, a foraminous core elementin said vat, means for introducing a liquid suspension of pulp fibersbetween the inner surface of the vat and the outer surface of the coreelement, means for withdrawing liquid which passes through theforaminous core element leaving a body of fibrous material thereon, anexpansible and contractable, non-foraminous mould element, leversconnected to said mould element at circumferentially spaced points, acasing surrounding said mould element, pivotal connections on saidcasing for said levers, a ring around said casing, a hydraulic ramconnected to said ring, a cylinder for said ram, a liquid reservoir, atubular connection between the cylinder and said reservoir, means forinterrupting said tubular connection, means for contracting the mouldelement to compress the fibrous body on the core element, means forexpanding the mould element, said interrupting means limiting expansionof said mould element, means for raising the mould element, and theopening of said interrupting means enabling further expansion of themould element to facilitate the release of the fibrous body.

5. Apparatus for forming hollow bodies by aspiration of a liquidsuspension of fibrous pulp comprising, a vat, a foraminous core elementin said vat, means for introducing a liquid suspension of fibrous pulpbetween the inner surface of the vat and the outer surface of theforaminous core element, means for withdrawing the liquid which passesthrough the foraminous core element leaving a body of fibrous materialdeposited thereon, an expansible and contractable non-foraminous mouldelement and having spaced segmental elements of relatively rigidmaterial, levers connected to the segmental elements, a casingsurrounding said non-foraminous mould element and secured to its lowerend thereof, a seating surface on the lower end of the casing, a seatingsurface carried by the vat engaging with the seating surface on thecasing, pivotal connections on the casing for the levers, ringsextending about the chamber adjacent to its upper and lower end, aconnection between each of the levers and the adjacent ring, a hydraulicram secured to each of the rings, cylinders in which such rams operate,a liquid reservoir, tubular connections between the cylinders and saidreservoir into and from which liquid will be displaced as the result ofmovement of the levers and rings in consequence of the expansion andcontraction of the mould element, means for interrupting the connectionbetween the cylinders and the reservoir to maintain the levers in theposition into which they mould element, means for raising the mouldelement, and the opening of said interrupting means enabling furtherexpansion of the non-foraminous mould element to facilitate the releaseof the body of fibrous material.

MAURICE GEORGE ROBERT NEWBOULD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 293,220 Bodge Feb. 12, 18841,637,532 Oliver et a1. Aug. 2, 1927 2,337,574

Sloan et al. Dec. 28, 1943

